Vat dyestuffs of the 2.2&#39;-indole-thionaphthene-indigo series



Patented Nov. 13, 1928.

. UNITED STATES I 1,691,660 PATENT. OFFICE.

CARL ERA-USS, OF LEVERKUSEN-ON-THE-RHINE, GER'MANY, ASS IGNOR TO GRASSELLI DYESTUFF CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE.

VAT DYESTUFFS THE 2.2-TNDOLE-THIONAPHTHENE-IND'IGO SERIES.

Ho Drawing. Application filed June 11, 1327, Serial No. l98,3pfi,. and ;sin@erznany June 15, 1926.;

My present invention relates to new vat dyestuffs of the 22-indole-thionaphthene-' indigo series. i

I have found that by brominating dyestuffs I of the general formula:

-. x Y i -i Y wherein one X stands for an alkyl-g'roup, the other two Xs and Ys stand for hydrogen, except for two which are bromine. I wish it to be understood that the position of the bromine atoms is not certain. (Probably one bromine atom is standing in the benzene nucleus of the indigo, residue, theother broexpo mine atom in the benzene nucleus of t-l1'6.'---

thionaphthene residue. I A For the'brominatingpr'ocess' I prefer'to use a temperature of about 10-15 ,C. while 40 addin the bromine/to the sulfuric acid-s'olution 0 the 2:2 -indole-thionaphthene-indigocompound and then to raise slowly the temperature to about 4050 C. The invention is illustrated by the following example, without limiting itthereto:

- 40 parts by weight of bromine are added with stirring to a solution of 30 parts by weight of 7 -methyl-2.2-indole-thionaphthene-indigo in 480 parts by weight of 96% sulfuric acidat from 10-15 0., after which stirring is continued for about 10 hours. The temperature is then raised by 5 per hour with continued stirring,until a temperature of 40 C. is attained, which is maintained for another hour, afterwhich the whole is poured ing and to light.

o concentrated sulfill atiid into te t r d h iiu iyi ere .Qfi,

washed and'dried. The yield amounts-i120 about 45 parts by'weight of dry dyestulf; whlch'is'shown by analysis to be a-dibromo d i ti The new dyestufi is resumed Qfl l iii following formula It is'in a dry state a violet powder soluble shades of good fastness to chlorine, to boilso I claim 1. The new dyestufis corresponding probably to the general formula:

wherein one stands for an alkyl-group,

"theiother two Xs and Ys stand forhydrogen, eiic'ept;;for two which are bromine, which are 1n a dry staterviolet powders soluble in 'th reenish-blue color dyeing-"the aiumal v 3 from a yellow vat beautifuliclear violet shades of good fastness' to' chlorine, to boiling, and to light, and which-are obtainable'by bro-"- minating dyestuffs of the general formula:

wherein one X stands'for an alkyl-group, and no,

-the other two Xs for hydrogen in sulfuric acid by means of bromine in quantities which suflice to cause the substitution of two bromine atoms.

2. The new dyestuffs corresponding probably to the general formula;

wherein one X stands for a methyl-group, the

other two Xs and Ys stand for hydrogen, except for two which are bromine, which are in a dry state violet powders soluble in concentrated sulfuric acid with greenish-blue color dyeing the animal and vegetable fibre from a yellow vat beautiful clear violet my hand.

formula which is in a dry state a violet powder soluble I inconcentrated sulfuric acid with greenishblue color dyeing the animal and vegetab le.

fibre from a yellow vat beautiful clear violet shades of good fastness to chlorine, to boiling and to light.

In testimony whereof I have hereunto set I CARL KRAUSS. 

